Combustion of waste fuels.



A. c. L. EKSTRM.

COMBUSTION OF WASTE FUELS.

APPLICATION HLED AU8.6. 1918.

Paten ted Fb.25, 1919.

perr

OFFICE.

COMBUSTION OF WASTE FUELS.

1295,&55.

Specification of Letters Patent.` Patented Feb. 25, 1919.

Application filed August 6, 1918. I Serial No. 248333.

To all 'who-m z' may concern: i

Be it known thatI, AXEL C. L, EKSTBM, a citizen of the United States, residing at Ballston Spa, in the county of Saratoga, State of New York, have invented certaln new and useful Improvements in the Coinbustion of Waste Fuels; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the sa1ne The present invention has for Its ob ect to mix and burn waste fuels, whose combustion individually, is impracticablc, so that, by the practice of the invention a law cost fuel is obtained that may be'economically burned, as hereinafter described, although its constituent ingredients, by themselves, are recognized as being incapable of successful use as a fuel by any' usual or ordinary method of combustion.

At every locomotive cleaning pit or ash dump, or where wastefully operated boilers are in operation, a large tonnage of refuse, containing a high percentage of combustible material is available in the form of unburned bituminous coal, or coke, or anthra` cite coal but partly burned. When this com bustible material is screened out, by either the wet or dry process, it will not make a successful fuel capable of carrying a sustained fire, because of its inherent clinkering characteristic, resulting in a spotty fire indicating that the combustion is not complete. The incompleteness of the combustion is due to the clinkering referred to which tends to close up the fuel bed, depriving it of its open character and correspondingly preventing successful combust'on. Similar clinkering characteristics are likewise inherent in other bituminous fuel wastes, such as coke oven screenings, the product known as coke breeze. In so far as I am aware, it has been heretofore found impracticable to utilize the NVaste products referred to for the production of a satisfactory boiler fuel.

At every anthracite mine, after all of the prepared sizes have been taken out, and after all of the regular commercial steam sizes have been taken out, there is a large waste tonnage (so-called slush) which is carried ofl from the property in liquid shape, but which carries as high as of solids when the slush is passed through a screen of 3/64ths inch mesh. These solids contain a large percentage of useful combustible material, after the water has been' dfained out. The solids obtained are in the shape of coal dust mixed with clay and other impurities. It is impracticable to use it alone upon a boiler fuel bed for the reason that the individual particles areso light that with the employment of the'usual forced draft, the partcles Will to a very large eXtent pass through the boiler fiues before combustion has taken place.

I have discovered that by appropriately combining the ash waste or coke oven wa ste above referred to With the mine waste described, a composite fuel is obtained of such a character that it can be burned to great advantage as a boiler fuel, when the respective wastes are combined in such proportions as to not only obviate their individual deficiencies for boiler firing, but even to utilize said individual deficiencies for the purpose of mutually correcting or compensating for each other. Thus, the clinkering characteristic of the 'ash waste or coke breeze is made available to serve as a binder for the light particles of the anthracite mine waste, whereas the higher percentage of carbon present in the anthracite mine waste so raises the total carbon content of the mixture as to permit obtaining the ,required heat units per voluine of the composite miXture. a

In practice, I employ from 10 to 20% of the bituminous ash wastes to 90 to 80% of the anthracite mine wastes. As noted, the main function of the ash waste is to serve as a binder for the anthracite mine waste, and the relative percentages of the two kinds of wastes making up the composite fuel will at all times be so adjusted as to sup'ply the more or less varyng requirements of the binding materials necessary to hold the dust containing the higher per cent. of carbon in position until the combustion has taken place.

e In the aocompanying drawing, I have indicated a form of grate-bar of a type that I have found fully adapted to the successful combustion of the composite fuel described.

In said drawing:

Figure 1 rep'resents, in side elevation, a general view of a grate made up of a series of said grate-bars and their supports;

Fig. 2 represents a top plan View of an intermediate member of the series;

Fig. 3 represents a section on the line 3-3 of Fig. 2; and Fg. 4 is a section on the line` Referrng to the drawing it may be noted that grate-bars are provided With a series of Slots a. These slots should preferably be 1/16 of an nch Wide, and not more than 5 (34: of an inch Wide at their upper plane, and should Widen downwardly, as shoWn,-the object being to have the slots sufhciently small to permt the bar to support the fuel mechancally and yet secure freedom from losses of coal through the bars, While at the same time giving them the necessary supply of air to'secure complete com bustion, the furnace 'being otherwise of any suitable standard design utilizable With forced draft. The grate-bar shown in the drawing' provides approxmately 11% of air space, which is sufiicient to pass the necessary supply of air to obtain the practically complete com'buston desired.

Having thus described my invention, What I claim is:

l. A composite fuel for stean boilefurnaces, comprsng anthracte mine Waste admiXed With a clinkerng ash Waste of the kind described in such proportons that the ash Waste Will act as a binding agent to maintain the anthracte mine w aste in position during the com'bustion of the composite fuel; substantally as described.

A composite fuel for steam boiler furnaces, comprising from 80 to 90% of anthracite mine Waste and 10 to of clinkering ash Waste; substantially as described.

In testimony Whereof I aflix my signature.

AXEL C. L. EKSTRM.

copies of this patent may be obtaied for five cents each, by addressg the commissioer of Patents. Washington, D. C. 

